1. Technical Field
The present invention relates to a cooling device, a substrate, and electronic equipment.
2. Background Art
Conventionally, various structures for cooling a heat generating electronic component such as a CPU have been proposed.
For example, a portable computer 1 shown in FIG. 18 is equipped with a box-shaped housing 10 formed of synthetic resin, a TCP (tape carrier package) 11 which is accommodated in the housing 10 and which is a CPU generating heat during operation, and a heat sink 12 accommodated in the housing 10 and adapted to dissipate the heat conducted from the TCP 11.
The heat sink 12 has a radiating portion 13 exposed to the exterior of the housing 10. In FIG. 18, reference symbol 10a indicates an upper housing, reference symbol 10b indicates a lower housing, and reference symbol 13a indicates an electric fan (refer to, e.g., Patent Document 1).
The portable computer 1 can efficiently dissipate the heat of the circuit element to the exterior of the housing 10, and is reasonably compatible with a reduction in the size of the housing 10.
A personal computer 2 shown in FIG. 19 has an equipment main body 15 containing a main printed circuit board 18 on which semiconductor packages 16, 17 are mounted as heat generating components, and a cooling unit 19 for cooling the heat generating components.
The cooling unit 19 has a radiating plate 20 arranged so as to oppose to the heat generating components and the main printed circuit board 18, and a cooling fan 21 mounted to the radiating plate 20.
The cooling fan 21 sucks in the air within the equipment main body through the periphery of the heat generating components and the radiating plate, and discharges it to the exterior of the equipment main body through an exhaust port 22. The cooling fan 21 is arranged such that the exhaust port 22 directly communicates with exhaust holes 23 formed in the equipment main body (refer to, e.g., Patent Document 2).
This small-sized electronic equipment can efficiently cool the heat generating components and achieve a reduction in noise.
FIG. 20 shows an information processing equipment 3, in which there is arranged a tubular radiating duct 25 formed of a material of high heat conductivity, with its ends being air-tightly connected to an intake port 26a and an exhaust port 26b of a cabinet 26 through the intermediation of gaskets 27, etc.
Inside the equipment, the radiating duct 25 is arranged so as to be in contact with heat generating components 28 and by forming an external air flow inside the radiating duct 25 by using a fan motor 29 or the like, heat radiation from these components is realized, and isolation from the external air is possible, thus achieving an enhancement in waterproof and dustproof performance (refer to, e.g., Patent Document 3).
In the information processing equipment 3, it is possible to cool the heat generating components 28 inside the equipment while achieving an enhancement in dustproof and waterproof performance, so that it is applicable to an information processing equipment that is often used outdoors.
Further, FIG. 21 shows an electronic equipment 4, which has a cooling unit 30. In the cooling unit 30, heat is transferred to a heat sink 34 by an endothermic plate 32 and a heat pipe 33, and the heat sink 34 is heated through this heat transfer.
The heat sink 34 thus heated receives an air flow formed by a cooling fan 35 inclined by a fan support portion 34a thereof to be thereby forcibly cooled, and the air warmed through this forced cooling is guided substantially in the horizontal direction by an exhaust passage 34e before being discharged to the exterior of the housing through an exhaust port provided in the housing.
Through this exhaust, it is possible to prevent local heating of a portion situated above the CPU mounted to the endothermic plate 32, with the result that it is possible to prevent an unpleasant feeling from being given to the fingertips of the operator (refer to, e.g., Patent Document 4).
[Patent Document 1]
JP 10-11174 A
[Patent Document 2]
JP 2001-14067 A
[Patent Document 3].
JP 11-194859 A
[Patent Document 4]
JP 2000-227822 A
However, in the conventional portable computer 1 shown in FIG. 18, the TCP 11 and the heat sink 12 are at positions spaced apart from each other, so that when a CPU of large heat generation amount as used in present-day notebook personal computers is used, there is a fear of this CPU not being cooled to a sufficient degree.
In the personal computer 2 shown in FIG. 19, it is necessary to cut out the portion where the cooling fan 21 of the main printed circuit board 18 is to be installed, which leads to a decrease in the mounting area of the main printed circuit board 18.
In the information processing equipment 3 shown in FIG. 20, the heat generating parts 28 are cooled by the air passing through the interior of the heat radiating duct 25, resulting in a poor cooling efficiency.
In the electronic equipment 4 shown in FIG. 21, it is possible to effect cooling by using the axial flow cooling fan 35 of low unit cost while achieving a reduction in installation height. However, the CPU and the cooling fan 35 are mounted on the same surface of the substrate, which leads to a problem in that the mounting area of the substrate is reduced.